The 5K stutter cutout misfire stumble breakup Thread [Merged 7-8]

[Newlogics]

My project 92 Talon just wouldn't be nice to me.

I figured that my smoking problem was due to my turbo leaking oil, since upper IC pipe had whole bunch of oil in it.

Now more porblems arize....

1st: It wouldn't idle normally, instead it revs up to 2K and drops back to 1K every like 2 sec. if idle is adjusted to be lower then 1100 rpm

2nd: When rmp reach 5K under WOT, it hesitates violently. As soon as rpms drop a bit, it's fine again.

(The good thing I fix the unlock buttons, 'cause it had shaved handles and you couldn't get inside by any means except a trunk....)

 

[92awddsm]

Do you have an afpr? Has it been doing this since you installed the 255? I had the same thing problem with both of my dsm's, just different causes between the 2.. The first time was on my 93. The oring on the pump got pinched during the install and was leaking. It would spool up and rune well untill about 45-5k rpm. Then it would start breaking up. On my 92, it ended up being to high of fuel pressure. My gauge was faulty and was reading 35psi base when in reality, it was about 50 psi base.

 

[Spoolio]

i didnt install the 255 yet, i wrote that into the profile the day i got the FP in my hands cause i thought i was installing it, but i never did cause i was having other problems with my car, im running the stock fp now,

 

[Spoolio]

i belived that are gapped at 28-30ish

 

[44pirate]

How old are the plugs and wires?
When was the last time you boost leak tested it?
Do you have a logger if so what was it logging?

 

[Spoolio]

im gettin knock at partial throttle and bad knock at wot around 4500rpms, i just changled the plugs and wires yesturday, and theres no major boost leak.

 

[PsychoticDead]

well, i just got my car started tonight, it needs a tune up bad. its got a little miss because one of the plug wires short out a little bit. but my real problem is when the turbo spools up, about 5k rpm and up is when i really notice it. It just loses all the power and its a dog, it will still rev up but takes forever under a load. in neutral, or clutch in, it will get up there no problem, up to 8.5k. what could be the problem? everyonce in a while it will kinda cut out for a second but it will go and rev like a dog still. this is my first import and first turbo car. so any help is much appreciated.

thanks

 

[twack]

Well for starters get your wires fixed, dont settle! But your problem is probably a boost like and a million others will probubly tell you that. Do a boost leak test, if you cant do that right now at least take off all your couplers and clamps and redo them tight. but you need to get a boost leak tester.

 

[HustlerTalon]

boost leak for sure.

 

[PsychoticDead]

so whats an easy way to test for a boost leak? i know on a chevy, chevy guy, you can use brake clean on the vacuum lines and such and if it revs or dies then thats where the leak is....but how would i go about testing a turbo leak?

 

[PsychoticDead]

and also, would not having the balance shaft belt on have any affect? I plan on doing the eliminator plate on it soon but just ran it without the belt...bad idea?

 

[timloomis]

Theres 2 balance shafts in there,one is driven by the oil pump.If you can stand the vibration,it's ok.

 

[PsychoticDead]

well, thanks alot to everyone, I got the car up and running now...time for a tune up and oil change. then off to the track i go, as long as its not raining!

 

[dsmfreak555]

I noticed something the other day when i made a quickpull in 1st gear, after around 5k the cars stops pulling hard and seems to just rev. now granted when i start hitting boost i think i heard a loud continous pssssshhing type sound so i think it might be a boost leak at the bov cause i check all my intercooler piping and theyre all good(i making a boost leak tester tommorrow to test the whole systems just to make sure, any advice? damn i really need a logger, maybe timings being pulled? or just running crappy cause its too rich up top? any advice would help

 

[jking29]

I would check your compressor wheel for play also when you do that leak test. If the boost leak was that bad, you would most likely hit fuel cut and feel like hitting a brick wall. What does your boost gauge say when it happens? What do the plugs look like? How old are the wires?

 

[95blackGsTurbo]

Loss of power like that is usually timing being pulled. Get back to us on the test though.

 

[clipsedrag]

I had a problem like this. But mine wasnt any of the suggestions. Mine ended up being my clutch being fried. It was pulling fine up until higher rpms then you could hear the boost but you wouldnt gain any speed. My clutch disk and pressure plate where slipping under the boost. If you smell near your engine bay, a burning clutch smells like asbestos (which smells like your brakes after you ride them hard.)

 

[Blue95GST]

not sure if it has to do with timing being pulled, and if that loud psshh sound was a boost leak that big, you wouldnt feel much pull, that sound is most likely just the air rushing through the piping, granted it is silicon, i can hear mine still. Most likely your clutch is slipping under boost or your wheels are losing traction and you just cant hear it. But still check everything just to be safe

 

[Red97Eclipseboy]

If you had a 2g, I'd say it's just the T25. It could be the clutch like they said.

 

[Blue95GST]

, yea but the t25 doesn't max till about 6400, depending on boost leaks

 

[dsmfreak555]

alright i just have to say thanks to all of you for the quick replys and good info, first i have a huge boost leak at my freakin BOV! that darn thing will leak after 11psi,( used a boost gauge to see how when i get leaks on my homemade boost leak tester). also i made like 3 or 4 hard pulls in 1st and 2nd then pulled over and guess what smelly clutch so yeah looks like im screwed pocket book wise since i have to buy another ssqv( my uncle has our welder to weld on a new flange for 1g bov, and a stinking clutch(it was time to upgrade anyway) thanks for the help

 

[calreef18]

Hello all, I'm probably going to answer my own question, but I'm looking to get some opinions anyways. I have a 14b in my 2g and at 15-16psi boost I get a short but loud pop at approximately 5k rpm. Accompanying it is a jerk to the car. When I turn the boost down to 14psi, I no longer have it, so that's where the car is at now. I have boost leak tested and passed fine, my instincts now say to recheck the gaps on the plugs I just put in(was using a slide measurer) in case the spark was getting blown out because of too large a gap on the ngk bpr6es, after that I'm going to try and test and or replace the plug wires. I made one pull at 16psi that looked good on the logger and no hesitation, but since its an auto the car downshifted and shifted up twice. When I did a long pull in 3rd or 2nd I started to get the pops/hesitation again, only does it once on each pull at WOT. No CEL's or anything like that, is it most likely the plug gap or wires like I'm suspecting?

 

[DROOPY209]

what does your timing look like?

Can you post a log?

 

[calreef18]

Sure can. I haven't touched boost at all since I turned it down, and now thats its night and colder, for some reason I hit the same sorta misfire, so I'm gonna try it again tomorrow when its warmer in the day and see if the affects it. Here is a log, sorry the data points are so few:
rpm o2v timing airflow
2944 .97 8 22.39
4316 .97 9 24.01
4728 .97 10 26.85
5172 .97 12 26.14
5500 .97 13 29.84

And then i got off the throttle after 5500 since I heard the misfire around 5k.

Here is a log from today where I didn't have any misfire:

rpm o2 timing airflow
2816 .93 8 24.58
4660 .95 10 26.40
5140 .95 12 28.68
5572 .95 13 29.80
5916 .95 15 30.36
6212 .95 15 30.98
6472 .93 16 31.46

If everything checks out tomorrow I'm gonna give a go at backing out the maf screw a little.

 

[Fitz7099]

It could possibly be fuel cut, but it seems unlikely since you are running a lower boost. What size injectors are you running? What kind of fuel pump?

The same thing happened to my GSX with my B16G. I turned the boost down a by 2-3 PSI and it hasn't happened since.

 

[calreef18]

Stock 450cc injectors and rewired stock fuel pump.

Ran another boost leak test today and the throttle body shaft seals are leaking. Off to the hardware store